Magnitude and pattern of hypertension in the Niger Delta: A systematic review and meta-analysis of community-based studies

Background Emerging evidence found that health inequality in the Niger Delta region in Nigeria has continued to worsen due to epidemiological and environmental risks transitions. This study aims to provide an up-to-date review and the secular trends of hypertension prevalence in Niger Delta. Methods We systematically searched databases of MEDLINE, EMBASE, African index Medicus and African Journal online from inception to December 30, 2016 for population-based studies providing prevalence estimates of hypertension in the Niger Delta. Eligible studies were included in a random-effect meta-analysis of prevalence and secular trend. The review was reported according to MOOSE guideline. Results Overall, 34 eligible studies comprising of data on 32715 participants with mean-age of 38.43 ± 2.0 years were identified and included in the meta-analysis. The pooled result showed that across study settings, the prevalence of hypertension in rural population tended to be higher than those in urban areas, 32.0% (95% confidence interval (CI) 25.13-39.28) vs 24.07% (95% CI 18.13-30.58), however, the difference did not reach a statistical significant level, (P < 0.183). The overall mean SBP was 130.15 (95% CI 126.85-133.45) mmHg, and the DBP was 80.72 (95% CI 78.45-82.95). The estimates also vary significantly in men compared to women; 30.26% (95% CI 23.76-37.17) vs 22.99% (17.60-28.86), P < 0.0001, and among those older than 65 years compared to those aged 45-64 years, and more than 2-fold compared to those between 15-44 years, P < 0.001. We also observed a continuous increase in prevalence of hypertension in the region (trend = 0.139, P = 0.0001), such that for every 10 years increase in participants' mean age, the prevalence of hypertension increases by 10.43% (95% CI 5.73-15.14), P < 0.001. Conclusions This study found evidence that hypertension is a major public health issue in the Niger Delta communities suggesting a positive relationship between socio-economic and lifestyle factors. Improved surveillance and care, as well as better management of the underlying risk factors, primarily undetected or uncontrolled high blood pressure, remains an important public health priority.